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US4627094A Expired / Lapsed US ⏱️ 0.0 years remaining

Electronic audio signal processor

Assignee: SR&D Inc
•
Filing: 1985-06-17
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Granted: 1986-12-02
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Expires: 2005-06-17
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Abstract

Abstract In an electronic audio signal processor suitable for electrical instruments such as electrical guitars, there is provided an improved pre-amplifier and compressor circuit which compresses the amplitude level of an inputted audio signal so as to provide lower noise better weak note recovery and improved high end boost, for low volume signals when the output thereof is fed through a distortion amplifier. The compressor circuit includes an op amp and feedback FET transistor.

Inventors

  • 👤 Donald T. Scholz

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-10 02:17
CPC Classifications
G; G10; G10H; G10H3/00; G10K; G10K15/00; G10K15/08; G10K15/12

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 193 words
An electronic audio signal processor for processing signals in the audio frequency range, comprising: a high pass audio filtering circuit for receiving an electrical audio input signal; an audio signal compressor circuit for receiving the output of said high pass audio filter and for producing an output signal, said compressor circuit comprising an amplifier having first and second inputs with the first input of the amplifier for receiving the output of said high pass audio filter, and a feedback circuit comprising a semiconductor control transistor connected in series with impedance means, said feedback circuit connecting from the output of said amplifier to said second input thereof, said feedback circuit adapted to control the compression of the amplitude range of the signal appearing at the first input of said amplifier, said semiconductor control transistor having an output electrode coupled to said impedance means, said impedance means comprising an R-C circuit for providing both noise suppression and high end boost at low volume, said R-C circuit comprising at least one resistor, at least one capacitor and conductor means connecting the resistor and capacitor in parallel between the transistor output electrode and said amplifier second input.
Claim 2
Dependent Claim 193 words
An electronic audio signal processor for processing signals in the audio frequency range, comprising: a high pass audio filtering circuit for receiving an electrical audio input signal; an audio signal compressor circuit for receiving the output of said high pass audio filter and for producing an output signal, said compressor circuit comprising an amplifier having first and second inputs with the first input of the amplifier for receiving the output of said high pass audio filter, and a feedback circuit comprising a semiconductor control transistor connected in series with impedance means, said feedback circuit connecting from the output of said amplifier to said second input thereof, said feedback circuit adapted to control the compression of the amplitude range of the signal appearing at the first input of said amplifier, said semiconductor control transistor having an output electrode coupled to said impedance means, said impedance means comprising an R-C circuit for providing both noise suppression and high end boost at low volume, said R-C circuit comprising at least one resistor, at least one capacitor and conductor means connecting the resistor and capacitor in parallel between the transistor output electrode and said amplifier second input.
Claim 3
Dependent Claim 22 words
An electronic audio signal processor as set forth in claim 1 wherein said impedance means comprises a pair of series connected resistors.
Claim 4
Dependent Claim 25 words
An electronic audio signal processor as set forth in claim 2 wherein said at least one capacitor couples in parallel with one of said resistors.
Claim 5
Dependent Claim 30 words
An electronic audio signal processor as set forth in claim 3 wherein said impedance means comprises a pair of capacitors each coupled in parallel with said respective pair of resistors.
Claim 6
Dependent Claim 28 words
An electronic audio signal processor as set forth in claim 4 wherein said audio filtering circuit includes a resistance on the order of at least 5 K ohms.
Claim 7
Dependent Claim 38 words
An electronic audio signal processor as set forth in claim 1 wherein said highpass audio filtering circuit comprises an audio filter having a relatively high value resistor associated therewith on the order of at least 5 K ohms.
Claim 8
Dependent Claim 39 words
An electronic audio signal processor as set forth in claim 6 including an input circuit at the amplifier including second and third resistors in series with the audio filter resistor and furthermore having a switch across said third resistor.
Claim 9
Dependent Claim 60 words
An electronic audio signal processor as set forth in claim 1 wherein said semiconductor control transistor comprises a field effect transistor said impedance means comprising a pair of capacitors and pair of resistors the capacitors each coupled in parallel with the resistors and further including switch contact means one in parallel with each of said parallel arranged resistors and capacitors.
Claim 10
Dependent Claim 48 words
An electronic audio signal processor as set forth in claim 8 including an input circuit associated with the field effect transistor and comprising a pair of resistors, a capacitor, and a pair of diodes connected in a series circuit to the control electrode of the field effect transistor.
Claim 11
Dependent Claim 29 words
An electronic audio signal processor as set forth in claim 1 wherein said R-C circuit includes a pair of series connected resistors and a pair of series connected capacitors.
Claim 12
Dependent Claim 34 words
An electronic audio signal processor as set forth in claim 10 including means for connecting the resistors in parallel with the capacitors and switch contacts also connected in parallel across the capacitors and resistors.
Claim 13
Dependent Claim 210 words
An electronic audio signal processor for processing signals in the audio frequency range, comprising: a high pass audio filtering circuit for receiving an electrical audio input signal; an audio signal compressor circuit for receiving the output of said high pass audio filter and for producing an output signal, said compressor circuit comprising an amplifier having first and second inputs with the first input of the amplifier for receiving the output of said high pass audio filter, and a feedback circuit comprising a semiconductor control transistor connected in series with impedance means, said feedback circuit connecting from the output of said amplifier to said second input thereof, said feedback circuit adapted to control the compression of the amplitude range of the signal appearing at the first input of said amplifier, said semiconductor control transistor having an output electrode coupled to said impedance means, said impedance means comprising an R-C circuit for providing both noise suppression and high end boost at low volume, said impedance means comprising a pair of series connected resistors, said impedance means comprising a pair of capacitors each coupled in parallel with said respective pair of resistor, wherein said impedance means also comprises switch contact means one in parallel with each of said parallel arranged resistors and capacitors.
Claim 14
Dependent Claim 210 words
An electronic audio signal processor for processing signals in the audio frequency range, comprising: a high pass audio filtering circuit for receiving an electrical audio input signal; an audio signal compressor circuit for receiving the output of said high pass audio filter and for producing an output signal, said compressor circuit comprising an amplifier having first and second inputs with the first input of the amplifier for receiving the output of said high pass audio filter, and a feedback circuit comprising a semiconductor control transistor connected in series with impedance means, said feedback circuit connecting from the output of said amplifier to said second input thereof, said feedback circuit adapted to control the compression of the amplitude range of the signal appearing at the first input of said amplifier, said semiconductor control transistor having an output electrode coupled to said impedance means, said impedance means comprising an R-C circuit for providing both noise suppression and high end boost at low volume, said impedance means comprising a pair of series connected resistors, said impedance means comprising a pair of capacitors each coupled in parallel with said respective pair of resistor, wherein said impedance means also comprises switch contact means one in parallel with each of said parallel arranged resistors and capacitors.
Claim 15
Dependent Claim 200 words
An electronic audio signal processor for processing signals in the audio frequency range, comprising: a high pass audio filtering circuit for receiving an electrical audio input signal; an audio signal compressor circuit for receiving the output of said high pass audio filter and for producing an output signal, said compressor circuit comprising an amplifier having first and second inputs with the first input of the amplifier for receiving the output of said high pass audio filter, and a feedback circuit comprising a semiconductor control transistor connected in series with impedance means, said feedback circuit connecting from the output of said amplifier to said second input thereof, said feedback circuit adapted to control the compression of the amplitude range of the signal appearing at the first input of said amplifier, said semiconductor control transistor having an output electrode coupled to said impedance means, said impedance means comprising an R-C circuit for providing both noise suppression and high end boost at low volume, said R-C circuit including a pair of series connected resistors and a pair of series connected capacitors, means for connecting the resistors in parallel with the capacitors, and switch contacts also connected in parallel across the capacitors and resistors.
Claim 16
Dependent Claim 200 words
An electronic audio signal processor for processing signals in the audio frequency range, comprising: a high pass audio filtering circuit for receiving an electrical audio input signal; an audio signal compressor circuit for receiving the output of said high pass audio filter and for producing an output signal, said compressor circuit comprising an amplifier having first and second inputs with the first input of the amplifier for receiving the output of said high pass audio filter, and a feedback circuit comprising a semiconductor control transistor connected in series with impedance means, said feedback circuit connecting from the output of said amplifier to said second input thereof, said feedback circuit adapted to control the compression of the amplitude range of the signal appearing at the first input of said amplifier, said semiconductor control transistor having an output electrode coupled to said impedance means, said impedance means comprising an R-C circuit for providing both noise suppression and high end boost at low volume, said R-C circuit including a pair of series connected resistors and a pair of series connected capacitors, means for connecting the resistors in parallel with the capacitors, and switch contacts also connected in parallel across the capacitors and resistors.
Claim 17
Dependent Claim 28 words
An electronic audio signal processor as set forth in claim 13 including a third resistor coupled from one of the resistors of the pair to a voltage potential.
Claim 18
Dependent Claim 25 words
An electronic audio signal processor as set forth in claim 14 including a third capacitor coupled in series from the control transistor to resistor pair.

References Cited (Backward Citations)

US3304369A Cited
US4072914A Cited
US4400583A Cited
US4363006A Cited
FR2485836A1 Cited
US4490691A Cited
US4538297A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-12-01 1990-06-02 1990-12-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-12-01 1994-06-02 1994-12-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-12-01 1998-06-02 1998-12-02 $7700.00 Window Closed / Lapsed

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